Analysis on Forming Characteristics of Cup-Shaped Thin-Walled Inner Gear Spinning

2010 ◽  
Vol 455 ◽  
pp. 544-547 ◽  
Author(s):  
L.Y. Sun ◽  
Bang Yan Ye ◽  
Q.X. Xia ◽  
Xiu Quan Cheng
Keyword(s):  
External Surface ◽  
Internal Surface ◽  
Tangential Direction ◽  
Radial Deformation ◽  
Forming Process ◽  
Number Of Teeth ◽  
Forming Characteristics ◽  
Near Net Shape ◽  
Thin Walled ◽  
Diameter Reduction

Spin-forming is a new near net-shape forming process for cup-shaped thin-walled inner gear (CTIG). The CTIG spinning was investigated by numerical simulation and processing experiments. The results show that the compressive deformation along tangential direction on the internal surface of part leads to a reduction in root circle of spun part; and the local loading and friction work result in the nonuniform radial deformation on the external surface of spun part. For spin-forming of CTIG with a small number of teeth, the diameter reduction is feasible for improving the forming quality of tooth groove, while the nonuniform radial deformation would cause concaves on external surface of part. For spin-forming of CTIG with a large number of teeth, the diameter reduction is not conducive to removing the part from the mandrel.

scholarly journals Forming Characteristics and Mechanism of Double-roll Rotary forging for Large Diameter and Thin-walled Metal Discs

2021 ◽  
Author(s):  
Zhongquan Yu ◽  
Chundong Zhu ◽  
Mingchao Chen ◽  
Site Luo
Keyword(s):  
High Surface ◽  
Large Diameter ◽  
Equivalent Stress ◽  
Low Noise ◽  
Forming Process ◽  
Eccentric Load ◽  
Geometric Shapes ◽  
Rotary Forging ◽  
Forming Characteristics ◽  
Thin Walled

Abstract Double-roll rotary forging is an emerging plastic forming technology based on rotary forging. Owing to the advantages of labor saving, small eccentric load, low noise and vibration, good uniformity, high surface quality and material saving, it is very promising for fabrication of large-diameter thin-walled disc. To date, few relevant research on the double-roll rotary forging technology of large-diameter thin-walled metal discs has been reported, and the forming mechanisms and process of disc workpieces remains uninvestigated. Herein, a 3D rigid-plastic finite element model (FEM) is established to simulate the fabrication process of large-diameter thin-walled disc, four geometric features appear in the forming process: “mushroom” shape, “upper drum” shape, “drum shape” shape and “lower drum” shape. Equivalent stress, equivalent strain and temperature field of these four geometric shapes are analyzed, and the forming mechanism of these four geometric shapes is revealed. The reliability and accuracy of FEM are verified through experiments and the four geometric shape features occur in the process are consistent with the simulation. The research results provide valuable guidelines for better understanding of double-roll rotary forging for the fabrication of large-diameter thin-walled discs.

scholarly journals Application of Modified Cores for Grain Refinement in Castings of Aircraft Turbine Blades

2017 ◽  
Vol 17 (3) ◽  
pp. 19-22 ◽  
Author(s):  
F. Binczyk ◽  
J. Cwajna ◽  
P. Gradoń
Keyword(s):  
Grain Refinement ◽  
Surface Defects ◽  
External Surface ◽  
Turbine Blades ◽  
Internal Surface ◽  
Aircraft Engine ◽  
Grain Refiner ◽  
Cast Part ◽  
Wax Pattern ◽  
Thin Walled

Abstract Paper presents the results of research on modified surface grain refinement method used in investment casting of hollow, thin-walled parts made of nickel based superalloys. In the current technology, the refining inoculant is applied to the surface of the wax pattern and then, it is transferred to the ceramic mould surface during dewaxing. Because of its chemical activity the inoculant may react with the liquid metal which can cause defects on the external surface of the cast part. The method proposed in the paper aims to reduce the risk of external surface defects by applying the grain refiner only to the ceramic core which shapes the internal surface of the hollow casting. In case of thin-walled parts the grain refinement effect is visible throughout the thickness of the walls. The method is meant to be used when internal surface finish is less important, like for example, aircraft engine turbine blades, where the hollowing of the cast is mainly used to lower the weight and aid in cooling during operation.

Design and Optimization of Honeycomb Corrugated Chaff Forming Roller

2014 ◽  
Vol 597 ◽  
pp. 213-218
Author(s):  
Xiao Ping Yang ◽  
Bo Zhong ◽  
Chang Jie Luo
Keyword(s):  
Analysis Software ◽  
Forming Process ◽  
Element Analysis ◽  
Time Curve ◽  
Forming Quality ◽  
Design And Optimization ◽  
Number Of Teeth ◽  
Stress Contour ◽  
Forming Characteristics ◽  
Good Agreement

Abstract. By analyzing the material properties and forming characteristics of the 0.8mm length side hexagon honeycomb corrugated chaff , we studied forming roller’s design and optimization while making corrugated chaffs used forming method and focus on the influence of the chamfer of teeth top edge and number of teeth to forming quality at the corrugated chaff corner .We used finite element analysis software ANSYS / LS-DYNA to simulate the forming process of corrugated chaff , studied the stress contour and stress-time curve of typical element, found the optimal chamfer of teeth top edge and number of teeth, then we used the designed forming roller to verify the effect of chaff forming . By comparison experimental and simulation results,we found good agreement between the two, when the chamfer of teeth top edge dj = 0.08mm, number of teeth z = 40, the chaff has the best forming quality .

A New Bionic Elastic Mandrel for Application in the Spatial Consecutive RDB with no Straight Line

2015 ◽  
Vol 25 ◽  
pp. 12-18 ◽  
Author(s):  
Lan Fang Jiang ◽  
Wei Ming Lin ◽  
Dong Hui Wen ◽  
Hong Liu ◽  
Cong Da Lu ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Internal Surface ◽  
Forming Process ◽  
Straight Line ◽  
Space Saving ◽  
Thin Walled Tube ◽  
Bending Radius ◽  
Continuous Support ◽  
Thin Walled ◽  
Draw Bending

Thin-walled spatial bending tube can not only provide engineering design with higher flexibility and lighter structure, but also enhance the construction of space saving and aerodynamics improvement. Based on rotary draw bending technique, a new method for spatial consecutive bending with no straight line for thin-walled tube was put forward. Firstly, a new bionic elastic mandrel was developed by analyzing the structural characteristics of the squilla. It mainly consisted of bowl-shaped mandrel balls, an elastomer and a mandrel shank. The bowl-shaped mandrel balls, nested matching one another, generated a non-smooth surface which can provide continuous support for internal surface of the tube wall. It could also achieve small bending radius. The elastomer featured of certain bending stiffness and enough tensile strength. Secondly, a curved clamping die was advanced to clamp the spatial consecutive bending tube with no straight line effectively. Based on the shape of the bending tube after the former bending forming process, the curved clamping dies which can match the shape of the former bending tube were designed for the later bending. Lastly, bending experiments was performed. A thin-walled tube made of Q235 with two passes, one bending angle 90° and the other 180° was taken for example and the spatial consecutive bending tube with no straight line was successfully obtained. It is of significant importance in enriching the spatial bending tube technique and achieving the small bending radius.

Study of Dieless Radial Spinning for Thick-Walled Cylindrical Parts With External Grooves

2021 ◽  
Author(s):  
Famei Liu ◽  
Junsong Jin ◽  
Wei Rao ◽  
Ying Wang ◽  
Chang Gao ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Material Flow ◽  
Forming Process ◽  
Forming Quality ◽  
Spinning Process ◽  
Cylindrical Parts ◽  
Forming Characteristics ◽  
Thin Walled ◽  
Aluminum Alloy Tube ◽  
Orthogonal Tests

Abstract Thick-walled cylindrical parts with external grooves are common components in the automobile and aviation fields. Such components can be produced by pressing the outer surface of a spinning thick-walled aluminum alloy tube by the dieless radial spinning process. The forming characteristics in the spinning process and the effects of various process parameters on forming were studied by using orthogonal tests and finite element simulations. During the forming process, bulge and thickness reductions occur because of material flow. The results of an investigation of process parameter effects show that the stress yield ratio (ξ) had no significant effect on forming. However, the feed thickness ratio (η) and initial wall thickness of the tube (t0) crucially affected the forming quality (e.g., the heights of bulges and thickness reduction in the groove area). Thick-walled tubes presented different phenomena compared to the thin-walled.

Kerusakan Pada Material Pipa Air Bersih Akibat General Corrosion

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
M. N. Setia Nusa
Keyword(s):  
Chemical Composition ◽  
Failure Analysis ◽  
External Surface ◽  
Internal Surface ◽  
General Corrosion ◽  
Water Pipe ◽  
Corrosion Attack ◽  
Corrosion Failure ◽  
Environment Factor

Water pipe of 4.5” diameter and has been operated for 8 year having failure due to corrosion attack on its external and internal surface. It is conducted failure analysis to find out the cause of corrosion by having testing examination of visual fractography, metalography,, SEM EDAX, hardness and chemical composition. Testing and examination results show that the failure / corroded pipe has a for in of general corrosion on the external surface due to environment factor or ground factor arround the pipe and on the internal surface was influenced by excessive root weld creating protrude which then causing turbolens and deposite to accelerate corrosion attack.Pipa berdiameter 4.5” yang berfungsi mengalirkan air bersih dan telah beroperasi selama 8 tahun, terjadi kerusakan berbentuk korosi pada permukaan luar pipa dan permukaan dalam. Untuk itu dilakukan analisa kerusakan untuk mengetahui penyebab terjadinya korosi dengan pengujian dan pemeriksaan secara visual,Fractography, Metallography, SEM, EDAX, Uji Kekerasan dan Uji Komposisi Kimia. Hasil pemeriksaan dan pengujian pada pipa yang rusak / korosi berbentuk jenis general korosi pada permukaan luar pipa yang diakibatkan faktor lingkungan atau tanah disekitar pipa, sedangkan pada bagian dalam pipa dipengaruhi oleh adanya lelehan pengelasan yang kurang sempurna sehingga menimbulkan benjolan yang mengakibatkan aliran air didalam pipa tidak lancar sehingga terjadi turbolensi yang menimbulkan endapan dan mengakibatkan percepatan terjadinya korosi.Keywords: Pipe, environtment, turbolens, corrosion, failure

scholarly journals Experimental Determination of the Heat Transfer Coefficient of Real Cooled Geometry Using Linear Regression Method

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 180
Author(s):  
Asif Ali ◽  
Lorenzo Cocchi ◽  
Alessio Picchi ◽  
Bruno Facchini
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Linear Regression ◽  
Surface Temperature ◽  
Transfer Coefficient ◽  
External Surface ◽  
Internal Surface ◽  
Regression Method ◽  
Thermal Transient

The scope of this work was to develop a technique based on the regression method and apply it on a real cooled geometry for measuring its internal heat transfer distribution. The proposed methodology is based upon an already available literature approach. For implementation of the methodology, the geometry is initially heated to a known steady temperature, followed by thermal transient, induced by injection of ambient air to its internal cooling system. During the thermal transient, external surface temperature of the geometry is recorded with the help of infrared camera. Then, a numerical procedure based upon a series of transient finite element analyses of the geometry is applied by using the obtained experimental data. The total test duration is divided into time steps, during which the heat flux on the internal surface is iteratively updated to target the measured external surface temperature. The final procured heat flux and internal surface temperature data of each time step is used to find the convective heat transfer coefficient via linear regression. This methodology is successfully implemented on three geometries: a circular duct, a blade with U-bend internal channel, and a cooled high pressure vane of real engine, with the help of a test rig developed at the University of Florence, Italy. The results are compared with the ones retrieved with similar approach available in the open literature, and the pros and cons of both methodologies are discussed in detail for each geometry.

scholarly journals Mechanical properties of rotary swaged steel components

2021 ◽  
Author(s):  
Dhia Charni ◽  
Svetlana Ortmann-Ishkina ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Jérémy Epp
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Strain Curve ◽  
Dynamic Mechanical Properties ◽  
Process Conditions ◽  
Forming Process ◽  
Rotary Swaging ◽  
Surface Residual Stresses ◽  
Near Net Shape ◽  
As Stress

AbstractThe radial infeed rotary swaging is widely used as a diameter reduction forming process of axisymmetric workpieces, improving the mechanical properties with excellent near net shape forming. In the present study, rotary swaging experiments with different parameter setups were performed on steel tubes and bars under different material states and several resulting property modifications were investigated such as stress-strain curve, hardness, fatigue strength and surface residual stresses. The results show a significant work hardening induced by the rotary swaging process and an improvement in the static and dynamic mechanical properties was observed. Furthermore, the hardness distribution was homogenous in the cross section of the rotary swaged workpieces. Moreover, depending on the process conditions, different residual stresses distribution were generated along the surface.

scholarly journals Cold Forging Effect on the Microstructure of Motorbike Shock Absorbers Fabricated by Tube Forming in a Closed Die

2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui
Keyword(s):  
Material Flow ◽  
Cold Forging ◽  
Technological Parameters ◽  
Forming Process ◽  
Tube Forming ◽  
Shock Absorbers ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Of Products ◽  
Forming Defects

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.

Shell Body Nose Forming by Rotary Swaging Process

2011 ◽  
Vol 213 ◽  
pp. 221-225 ◽  
Author(s):  
Jeong Hwan Jang ◽  
Byeong Don Joo ◽  
Sung Min Mun ◽  
Young Hoon Moon
Keyword(s):  
Finite Element ◽  
Initial Thickness ◽  
Dimensional Changes ◽  
Rotary Swaging ◽  
Inside Diameter ◽  
Before And After ◽  
Forming Characteristics ◽  
Inner Diameter ◽  
The Given ◽  
Diameter Reduction

Studies on the forming characteristics by a rotary swaging process using the sub-scale specimens have been carried out to obtain a shell body nose of desirable quality. To analyze the changes of the nose thickness and length at the respective reduction of inside diameter, the finite element simulations were carried out. As a result, the desired target dimension is satisfied with the diameter reduction of more than 64 % for the given preform. The thickness of nose area increased up to 56.1 % from initial thickness of 2.62 mm to 4.09 mm after swaging. The values of the hardness before and after swaging were 208 HV and 325 HV, respectively. To analyze the dimensional changes (length and thickness) of nose area with decreasing inside diameter, the rotary swaging test was carried out for two different diameter reductions such as 65 % and 67 %. The lengths of nose area for the diameter reductions are 11.79 mm in 65 % and 12.53 mm in 67 %, respectively. At the diameter reduction of more than 67%, the crack occurs when the localized strain hardening reduces ductility in internal area. Therefore, the nose area should be formed from 64% to 67% reduction in target inner diameter.

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